Foundry molding material



E? STA E.

FREDERICK G. DOKKENYVADEL, OF COSHOCTON, OHIO.

No Drawing.

T0 aZZ whom it may concern Be it known that I, FREDERICK G. DoK- KENWADEL, a citizen of the United States, and a resident of Coshocton, in the county of Coshocton and State of Ohio, have invented a new and Improved Foundry Molding Material, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved composition of matter to be used as a foundry molding material with a view to insure the formation of castings which are exceedingly smooth, of a fine, dense grain, and practically free of pits,blow holes or other imperfections.

Another object is to provide a foundry molding material capable of withstanding the heat of the molten metal to allow repeated reuse of the molding material.

In order to produce the foundry molding material (commonly called molding or foundry sand) use is made of graphite (plumbago or black lead), or similar material, mixed with a base formed of marl lime, which is a natural deposit found at present in various parts of the United States and called molluskite, consisting mainly of small, crumbled shells of a probably extinct animal of the mollusk family. The molluskite deposit after being removed from its bed is preferably dried in a rotary or other drier of any approved construction, and by subjecting it to the heat and the action of the drier the material crumbles into powder form. If necessary, the powder may be further reduced by grinding it up but, as a rule, such operation is not necessary. The resultant powder is blown by a suitable blower into a large settling chamber in which the powder, settling in the remotest part of the settling chamber, is exceedingly fine and impalpable and is used as a base for the molding material. In practice, about three parts of the molluskite flour is mixed with one part of finely reduced graphite Specification of Letters Patent.

Application filed February 23, 1921.

Patented Au 8, 1922.

SeriaI 1%. 447,234.

Lime 50.15 per cent. Sulphur .27 per cent. Magnesium 1.53 per cent. Silica 2.60 per cent.

Alumina a- .24 per cent. Iron oxide .60 per cent.

About 4A per cent of unknown volatile matter disappeared in making the analysis.

The molluskite flour mixed with the graphite forms a very fine, impalpable molding material. which insures the formation of castings having exceedingly smooth surfaces and a fine grain and free of pits, blow holes, or other imperfections. Furthermore, the improved molding material is capable to readily withstand the heat of the molten metal during the casting operation particularly as the well known heat resisting qualities of the graphite protect the molluskite material and hence the molding material can be repeatedly used for molding purposes. The improved molding material is applied and used in the same manner as the usual sands, plumbago or similar materials now generally employed and hence further description of the operation is not deemed necessary.

It is understood that the molluskite ma terial is exceedingly cheap in comparison with plumbago or similar material and hence a large saving in foundry expense is had.

Having thus described my invention, 1 claim as new and desire to secure by Letters Patent The herein described foundry molding material comprising molluskite, 3 parts; and graphite, 1 part.

FREDERICK G. DOKKENWADEL. 

